Figure 2.

Absorption coefficient spectra and Tauc plots and relative linear fits. (a) Transmittance and reflectance spectra of 5-nm a-Ge QW (inset). Absorption coefficient
of a-Ge QW of different thicknesses together with the spectrum of a bulk-like 125-nm
a-Ge. (b) Tauc plots (symbols) and relative linear fits according to the reported Tauc law
(lines).